Large social network companies like Facebook gets a very high amount of images submitted each month. In 2013, Facebook received 350 Million photos from users each day, amounting to a total of 250 Billion photos, or 300 petabytes.
Moreover, wearable oameras (also known as life-logging cameras) are on the rise, and these devices generate a huge amount of images during an ordinary day, since they are always active.
This means that users are more and more likely to gather photos with similar content. Low cost of storage and mobile phone cameras being ubiquitous means that many users have an abundance of images stored but seldom retrieved. Even though the cost of storage has dropped over the years, the size (resolution) and amount of photos has increased at the same rate, still limiting the users. Considering life-logging scenarios, where users may store more than 1000 images each day, optimizing storage is of essence.